The Walt Disney Co. has become the first major media company to ban junk-food advertising on programming that targets children.

Building on a healthy-foods initiative in its theme parks, Disney imposed new standards for food and beverages advertised on Disney XD and during the Saturday morning programs on Disney-owned ABC television stations. Disney Channel and Disney Junior, which are not ad-supported but receive brand sponsorships, would also be covered under the nutrition guidelines, officials said.

Kanter Media, a research firm specializing in advertising, estimated the total amount of ad spending for this kind of advertising on Disney-owned channels and Saturday morning children's programming on ABC totaled $7.2 million in 2011.

First Lady Michelle Obama, who has made fighting the childhood obesity epidemic and promoting healthy eating a hallmark of her time in the White House, praised Disney's initiative at a Tuesday morning news conference at the Newseum in Washington.

"This new initiative is truly a game-changer for the health of our children," Obama said. "So, for years, people told us that no matter what we did to get our kids to eat well and exercise, we would never solve our childhood obesity crisis until companies changed the way that they sell food to our children. We all know the conventional wisdom about that. ... Today, Disney has turned that conventional wisdom on its head."

Six years ago, Disney instituted healthier food options at its theme parks in Anaheim and Orlando, Fla., automatically including carrots and low-fat milk in children's meals unless parents requested otherwise. Its consumer products division changed its licensed food program so that 85% of its offerings comply with the company's nutrition guidelines. It even chose to stop licensing its characters for McDonald's "Happy Meals," citing the links between fast food and childhood obesity.

Food and beverage advertisers who seek to promote their products on Disney Channel or Disney XD will be required by 2015 to meet guidelines regarding serving size, calories, fat and sugar content. The guidelines are aligned with federal standards promoting fruit and vegetable consumption and calling for limiting calories and reducing saturated fat, sodium and sugar.

"We've taken steps across our company to support better choices for families," Disney Chairman and Chief Executive Robert A. Iger said in a statement. "And now, we're taking the next important step forward by setting new food advertising standards for kids."

Obama said kids are exposed to food and beverage marketing that adds up to an estimated $1.6 billion a year, including many ads for foods that are high in calories and sugar but low in nutrition.

"Our kids are constantly bombarded with sophisticated messages designed to sell them foods that simply aren't good for them," Obama said. "And let me tell you, we know it works, right?"

Many parents make the effort to prepare nutritious meals and healthy snacks, Obama said, but when kids turn on their favorite shows, those efforts are undermined during the commercial break.

"That's why I am so thrilled about today's announcements," she said. "I am thrilled that Disney is stepping forward in such a big way."

Obama has used other children's television networks to get out her healthy-living message. Last year, she joined in Nickelodeon’s Worldwide Day of Play, an effort to get kids involved in healthy activities and away from the TV for at least three hours a day.

[For the Record, 12:36 p.m. June 5: An earlier version of this post indicated that the Disney Junior channel is ad-supported. It is not, but receives brand sponsorships.]